A new lineup of Nintendo 64 games will be headed to the Nintendo Switch Online + Expansion Pack service in the future, including titles from the Mario Party and Pokémon Stadium series. Pokémon Stadium and Pokémon Stadium2 will not be able to transfer Pokémon into these games though.

Source: https://www.nintendo.com/whatsnew/out-of-the-shadows-the-legend-of-zelda-tears-of-the-kingdom-launches-for-nintendo-switch-on-may-12-2023/